Linux/Unix Shell Scripting - Leer linea a linea un fichero y buscarla con grep

#!/bin/bash

for linea in $(cat $1)

do

grep "$linea" $2

done

sudo bash script.sh a.txt .b.txt

while read linea

do

   grep "$linea" "$2"

done < $1

while linea=$(line)

do

...

done < $1

#!/bin/bash

while read linea

do

i=$(grep "$linea" "$2")

if [ `grep $linea $2 | wc -l` -eq 0 ]

then

	echo "$linea:Not Found"

else

	echo "$i"

fi

done < $1

#!/bin/bash

while read linea

do

grep "$linea" "$2" || echo "$linea:Not Found"

done < $1